Merge pull request #626 from carpentries/frog-ins-notes-1

Improve instructor notes warnings

R/build_instructor_notes.R

@@ -5,14 +5,26 @@ build_instructor_notes <- function(pkg, pages = NULL, built = NULL, quiet) {
   path <- get_source_path() %||% root_path(pkg$src_path)
   lsn <- this_lesson(path)
   outpath <- fs::path(pkg$dst_path, "instructor-notes.html")
+
+  instructor_notes_exists <- any(grepl("instructor-notes[.]R?md$", list.files(path=path_instructors(path))))
+  if (!instructor_notes_exists) {
+    cli::cli_alert_danger("WARNING: instructors/instructor-notes.[R]md does not exist!")
+    return(invisible(NULL))
+  }
+
   already_built <- template_check$valid() &&
     fs::file_exists(outpath) &&
     !is.null(built) &&
     !"instructor-notes" %in% get_slug(built)
   if (!already_built) {
     page_globals <- setup_page_globals()
-    inote <- .resources$get()[["instructors"]]
-    inote <- inote[get_slug(inote) == "instructor-notes"]
+    inote_resc <- .resources$get()[["instructors"]]
+    inote <- inote_resc[get_slug(inote_resc) == "instructor-notes"]
+    if (length(inote) == 0) {
+      cli::cli_alert_danger("WARNING: instructors/instructor-notes.[R]md exists but is not referenced in your config.yaml `instructors` section.")
+      return(invisible(NULL))
+    }
+
     html <- render_html(inote)
     if (html != "") {
       html <- xml2::read_html(html)